You are here:
THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN
Citation:
Blackman, C F. AND S G. Benane. THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN. Presented at Annual Meeting of the Bioelectromagnetics, St. Petersberg, FL, June 1998.
Description:
THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN.
Harland and Liburdy (1) reported that 1.2-uT, 60-Hz magnetic fields could significantly block the inhibitory action of pharmacological levels of tamoxifen (10-7 M) on the growth of MCF-7 human breast-cancer cells in vitro. OBJECTIVE: With the cooperation of the originating laboratory , our goal was to independently test the tamoxifen and magnetic field effects on MCF - 7 cells reported by Harland and Liburdy (1 ). APPROACH AND METHODS: We followed the
detailed protocol provided by the original laboratory which included using cells from the original lab and the same lot of serum as in the original report. In both labs, mu-metal chambers screened ambient magnetic fields during treatments, allowing careful control of all fields to which the cells were exposed during testing. There were three deviations from the original protocol: a) our growth of stock MCF -7 cells was in a magnetically unshielded incubator, where the ambient 60- Hz fields were 0.2 uT as required by the protocol, b) we used Helmholtz rather than Merritt coils to generate the magnetic fields during our tests, and c) we counted the number of cells on each dish using a Coulter counter rather than a hemocytometer. Cells were plated on twenty-four 35-mm dishes, twelve with and twelve without 0.25 x 10-7 M tamoxifen. Six dishes with tamoxifen and six without were placed in each of two exposure chambers: Helmholtz coils inside a mu-metal box housed in a 5% CO2 incubator. One exposure chamber was energized with 1.2- uT , 60- Hz vertical magnetic fields and the other chamber was unenergized. Treatment was continuous until assays were performed. Cells were harvested on days 6 and 7 after plating, and counted in a blinded manner in a Coulter counter. RESULTS: In the unenergized chamber, tamoxifen reduced the cell growth by 32% and 42%, while in 1.2-uT 60-Hz fields, tamoxifen only reduced the cell growth by 22% and 26%, on days 6 and 7, respectively. DISCUSSION : These preliminary results are consistent with the reported results of Harland and Liburdy (1) which show a 33% and 40% inhibition ofMCF- 7 cell growth by tamoxifen in control conditions on days 6 and 7, respectively, and a nil and 18% inhibition in similar chemical conditions but under 1.2-~T 60-Hz magnetic field exposure. A critical element of this replication effort was the constructive communication established and maintained with the original investigators. A previous report by Harland and Liburdy (see 1) showing removal of melatonin-induced inhibition of MCF- 7 cell growth by similar magnetic field exposure has been successfully replicated by two independent laboratories (2,3).
This abstract foes not necessarily reflect EPA policy.